Improved insecticide formulations

Abstract

Insecticide formulation having improved chemical and physical stability and related method are disclosed. The insecticide formulation may include a plurality of microcapsule, each including at least one organophosphate insecticide (e.g., chlorpyrifos-methyl) at least partially surrounded by a polymer shell. The insecticide formulation may be used to control insect populations by singular or periodic applications. The microcapsule polymer shell of the insecticide formulation may be formed by combining a crosslinking amine and a hydrophobic monomer (e.g., an isocyanate) at a molar ratio of amine to isocyanate groups of less than about 1:1. The molar ratio of amine to isocyanate groups may be between about 0.3 to 1 and about 0.8 to 1.